Topics in Catalysis

, Volume 58, Issue 7–9, pp 424–434 | Cite as

The Dynamic Nature of Brønsted Acid Sites in Cu–Zeolites During NOx Selective Catalytic Reduction: Quantification by Gas-Phase Ammonia Titration

  • John R. Di Iorio
  • Shane A. Bates
  • Anuj A. Verma
  • W. Nicholas Delgass
  • Fabio H. Ribeiro
  • Jeffrey T. Miller
  • Rajamani GounderEmail author
Original Paper


Brønsted acid sites on Cu-exchanged zeolites can be titrated selectively using gaseous ammonia when NH3 saturation steps are followed by protocols that remove Lewis acid-bound and physisorbed NH3, such as purging in flowing wet helium at 433 K. NH3 titrates all H+ sites on small-pore chabazite zeolites (SSZ-13) and leads to the complete disappearance of infrared stretches for Brønsted acidic OH groups after saturation (433 K), in contrast with larger n-propylamine titrants that access only a small fraction (<0.25) of H+ sites on SSZ-13 under conditions sufficient to titrate all H+ sites on medium-pore ZSM-5 zeolites (323 K, 2 h). NH3 titration of the residual H+ sites present in Cu-exchanged SSZ-13 samples (Si/Al = 4.5, Cu/Al = 0–0.20) after oxidative treatments detects two fewer H+ sites per exchanged Cu2+ ion, as expected to maintain framework charge neutrality. NH3 titrants detect only one fewer H+ site (per Cu) after Cu-SSZ-13 samples undergo a reductive treatment in flowing NO and NH3 (473 K), however, indicating that each Cu2+ cation reduces to form a Cu+ and H+ site pair. In the context of low temperature (473 K) selective catalytic reduction (SCR) on high aluminum Cu-SSZ-13, we discuss the different mechanistic roles of residual H+ sites that remain after Cu2+ exchange, whose primary function appears to be NH3 storage, and of proximal H+ sites that are generated in situ upon Cu2+ reduction, whose role is to stabilize reactive NH4 + intermediates involved in the standard SCR oxidation half-cycle. We highlight how gaseous NH3 titrants can selectively count H+ sites on small-pore, Cu-exchanged zeolites and, in doing so, enable probing the dynamic nature of active sites and catalytic surfaces during SCR redox cycles.


Ammonia Brønsted acid site Copper-exchanged zeolites n-Propylamine Selective catalytic reduction Titration 



We acknowledge the financial support provided by the National Science Foundation GOALI program under award number 1258715-CBET. RG also acknowledges financial support from a Ralph E. Powe Junior Faculty Enhancement Award from the Oak Ridge Associated Universities, and from a Purdue Research Foundation Summer Faculty Grant. Support for JTM was provided under the auspices of the U.S. DOE, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences under contract number DE-AC0-06CH11357. We would like to thank Sachem, Inc. for their donation of the structure-directing agent used to synthesize SSZ-13, Dr. Yury Zvinevich for assistance constructing a custom-built acid site titration unit, Austin Tackaberry for assistance with SSZ-13 sample preparation, and Arthur Shih and Jonatan Albarracin-Caballero for assistance with some of the NH3 TPD experiments. Finally, we would like to thank Professor Mark E. Davis for continuing to lead by example and inspire his current and former colleagues to pursue creative research problems in catalysis.

Supplementary material

11244_2015_387_MOESM1_ESM.docx (252 kb)
Supplementary material 1 (DOCX 251 kb)


  1. 1.
    Davis ME, Lobo RF (1992) Chem Mater 4:756–768CrossRefGoogle Scholar
  2. 2.
    Davis ME (2002) Nature 417:813–821CrossRefGoogle Scholar
  3. 3.
    Rossin JA, Saldarriaga C, Davis ME (1987) Zeolites 7:295–300CrossRefGoogle Scholar
  4. 4.
    Montes C, Davis ME, Murray B, Narayana M (1990) J Phys Chem 94:6425–6430CrossRefGoogle Scholar
  5. 5.
    Davis ME (1991) Ind Eng Chem Res 30:1675–1683CrossRefGoogle Scholar
  6. 6.
    Korhonen ST, Fickel DW, Lobo RF, Weckhuysen BM, Beale AM (2011) Chem Commun 47:800–802CrossRefGoogle Scholar
  7. 7.
    Deka U, Juhin A, Eilertsen EA, Emerich H, Green MA, Korhonen ST, Weckhuysen BM, Beale AM (2012) J Phys Chem C 116:4809–4818CrossRefGoogle Scholar
  8. 8.
    Paolucci C, Verma AA, Bates SA, Kispersky VF, Miller JT, Gounder R, Delgass WN, Ribeiro FH, Schneider WF (2014) Angew Chem Int Ed 53:11828–11833CrossRefGoogle Scholar
  9. 9.
    McEwen JS, Anggara T, Schneider WF, Kispersky VF, Miller JT, Delgass WN, Ribeiro FH (2012) Catal Today 184:129–144CrossRefGoogle Scholar
  10. 10.
    Kispersky VF, Kropf AJ, Ribeiro FH, Miller JT (2012) Phys Chem Chem Phys 14:2229–2238CrossRefGoogle Scholar
  11. 11.
    Andersen PJ, Bailie JE, Casci JL, Chen HY, Fedeyko JM, Foo RKS, Rajaram RR (2010) US Patent US20100290963 A1Google Scholar
  12. 12.
    Kwak JH, Tonkyn RG, Kim DH, Szanyi J, Peden CHF (2010) J Catal 275:187–190CrossRefGoogle Scholar
  13. 13.
    Bull I, Koermer GS, Moini A, Unverricht S (2009) US Patent US20090196812 A1Google Scholar
  14. 14.
    Deka U, Lezcano-Gonzalez I, Weckhuysen BM, Beale AM (2013) ACS Catal 3:413–427CrossRefGoogle Scholar
  15. 15.
    Brandenberger S, Kröcher O, Tissler A, Althoff R (2008) Catal Rev 50:492–531CrossRefGoogle Scholar
  16. 16.
    Kwak JH, Tran D, Burton SD, Szanyi J, Lee JH, Peden CHF (2012) J Catal 287:203–209CrossRefGoogle Scholar
  17. 17.
    Bates SA, Verma AA, Paolucci C, Parekh AA, Anggara T, Yezerets A, Schneider WF, Miller JT, Delgass WN, Ribeiro FH (2014) J Catal 312:87–97CrossRefGoogle Scholar
  18. 18.
    Sjövall H, Olsson L, Fridell E, Blint RJ (2006) Appl Catal B 64:180–188CrossRefGoogle Scholar
  19. 19.
    Choi E-Y, Nam I-S, Kim YG (1996) J Catal 161:597–604CrossRefGoogle Scholar
  20. 20.
    Huang HY, Long RQ, Yang RT (2002) Appl Catal A 235:241–251CrossRefGoogle Scholar
  21. 21.
    Rahkamaa-Tolonen K, Maunula T, Lomma M, Huuhtanen M, Keiski RL (2005) Catal Today 100:217–222CrossRefGoogle Scholar
  22. 22.
    Metkar PS, Salazar N, Muncrief R, Balakotaiah V, Harold MP (2011) Appl Catal B 104:110–126CrossRefGoogle Scholar
  23. 23.
    Long RQ, Yang RT (1999) J Catal 188:332–339CrossRefGoogle Scholar
  24. 24.
    Kustov AL, Hansen TW, Kustova M, Christensen CH (2007) Appl Catal B 76:311–319CrossRefGoogle Scholar
  25. 25.
    Dumesic JA, Topsøe NY, Topsøe H, Chen Y, Slabiak T (1996) J Catal 163:409–417CrossRefGoogle Scholar
  26. 26.
    Schneider H, Tschudin S, Schneider M, Wokaun A, Baiker A (1994) J Catal 147:5–14CrossRefGoogle Scholar
  27. 27.
    Bates SA, Delgass WN, Ribeiro FH, Miller JT, Gounder R (2014) J Catal 312:26–36CrossRefGoogle Scholar
  28. 28.
    Brandenberger S, Kröcher O, Wokaun A, Tissler A, Althoff R (2009) J Catal 268:297–306CrossRefGoogle Scholar
  29. 29.
    Gao F, Kwak J, Szanyi J, Peden CF (2013) Top Catal 56:1441–1459CrossRefGoogle Scholar
  30. 30.
    Woolery GL, Kuehl GH, Timken HC, Chester AW, Vartuli JC (1997) Zeolites 19:288–296CrossRefGoogle Scholar
  31. 31.
    Bagnasco G (1996) J Catal 159:249–252CrossRefGoogle Scholar
  32. 32.
    Topsøe NY, Dumesic JA, Topsoe H (1995) J Catal 151:241–252CrossRefGoogle Scholar
  33. 33.
    Topsøe NY, Topsøe H, Dumesic JA (1995) J Catal 151:226–240CrossRefGoogle Scholar
  34. 34.
    Zones SI (1985) US Patent US4544538 AGoogle Scholar
  35. 35.
    Gorte RJ (1999) Catal Lett 62:1–13CrossRefGoogle Scholar
  36. 36.
    Wang J, Yu T, Wang X, Qi G, Xue J, Shen M, Li W (2012) Appl Catal B 127:137–147CrossRefGoogle Scholar
  37. 37.
    Datka J, Gil B, Kubacka A (1995) Zeolites 15:501–506CrossRefGoogle Scholar
  38. 38.
    Katada N, Niwa M (2004) Catal Surv Asia 8:161–170CrossRefGoogle Scholar
  39. 39.
    Farneth WE, Gorte RJ (1995) Chem Rev 95:615–635CrossRefGoogle Scholar
  40. 40.
    Kresnawahjuesa O, Gorte RJ, Oliveira Dd, Lau LY (2002) Catal Lett. 82:155–160CrossRefGoogle Scholar
  41. 41.
    Kresnawahjuesa O, Heussner R, Lee C-C, Kuehl G, Gorte RJ (2000) Appl Catal A 199:53–60CrossRefGoogle Scholar
  42. 42.
    Parrillo DJ, Adamo AT, Kokotailo GT, Gorte RJ (1990) Appl. Catal. 67:107–118CrossRefGoogle Scholar
  43. 43.
    Gounder R, Jones AJ, Carr RT, Iglesia E (2012) J Catal 286:214–223CrossRefGoogle Scholar
  44. 44.
    Baiglow AI, Parrillo DJ, Kokotailo GT, Gorte RJ (1994) J Catal 148:213–223CrossRefGoogle Scholar
  45. 45.
    Xu B, Rotunno F, Bordiga S, Prins R, van Bokhoven JA (2006) J Catal 241:66–73CrossRefGoogle Scholar
  46. 46.
    Omegna A, Prins R, van Bokhoven JA (2005) J. Phys. Chem. B 109:9280–9283CrossRefGoogle Scholar
  47. 47.
    Omegna A, van Bokhoven JA, Prins R (2003) J. Phys. Chem. B 107:8854–8860CrossRefGoogle Scholar
  48. 48.
    van Bokhoven JA, Roest AL, Koningsberger DC, Miller JT, Nachtegaal GH, Kentgens APM (2000) J. Phys. Chem. B 104:6743–6754CrossRefGoogle Scholar
  49. 49.
    Hunger M, Engelhardt G, Weitkamp J (1995) Microporous Mater 3:497–510CrossRefGoogle Scholar
  50. 50.
    Zhao Z, Xu S, Hu MY, Bao X, Peden CHF, Hu J (2014) J Phys Chem C. doi: 10.1021/jp509982r Google Scholar
  51. 51.
    Dent LS, Smith JV (1958) Nature 181:1794–1796CrossRefGoogle Scholar
  52. 52.
    Olson DH, Kokotailo GT, Lawton SL, Meier WM (1981) J Phys Chem 85:2238–2243CrossRefGoogle Scholar
  53. 53.
    Pope CG (1990) Zeolites 10:28–31CrossRefGoogle Scholar
  54. 54.
    Verma AA, Bates SA, Anggara T, Paolucci C, Parekh AA, Kamasamudram K, Yezerets A, Miller JT, Delgass WN, Schneider WF, Ribeiro FH (2014) J Catal 312:179–190CrossRefGoogle Scholar
  55. 55.
    Doronkin DE, Casapu M, Günter T, Müller O, Frahm R, Grunwaldt J-D (2014) J Phys Chem C 118:10204–10212CrossRefGoogle Scholar
  56. 56.
    Moden B, Donohue J, Cormier W, Li H-X (2010) Top Catal 53:1367–1373CrossRefGoogle Scholar
  57. 57.
    Mihai O, Widyastuti CR, Andonova S, Kamasamudram K, Li J, Joshi SY, Currier NW, Yezerets A, Olsson L (2014) J Catal 311:170–181CrossRefGoogle Scholar
  58. 58.
    Kamasamudram K, Currier NW, Chen X, Yezerets A (2010) Catal Today 151:212–222CrossRefGoogle Scholar
  59. 59.
    Auvray X, Partridge WP, Choi J-S, Pihl JA, Yezerets A, Kamasamudram K, Currier NW, Olsson L (2012) Appl Catal B 126:144–152CrossRefGoogle Scholar
  60. 60.
    Topsøe NY (1994) Science 265:1217–1219CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • John R. Di Iorio
    • 1
  • Shane A. Bates
    • 1
  • Anuj A. Verma
    • 1
  • W. Nicholas Delgass
    • 1
  • Fabio H. Ribeiro
    • 1
  • Jeffrey T. Miller
    • 1
    • 2
  • Rajamani Gounder
    • 1
    Email author
  1. 1.School of Chemical EngineeringPurdue UniversityWest LafayetteUSA
  2. 2.Chemical Sciences and Engineering DivisionArgonne National LaboratoryArgonneUSA

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